ip_icmp.c revision 1.168
1 /* $NetBSD: ip_icmp.c,v 1.168 2018/02/08 09:32:02 maxv Exp $ */ 2 3 /* 4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Public Access Networks Corporation ("Panix"). It was developed under 9 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. 10 * 11 * This code is derived from software contributed to The NetBSD Foundation 12 * by Jason R. Thorpe of Zembu Labs, Inc. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 36 /* 37 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 38 * All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the project nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 */ 64 65 /* 66 * Copyright (c) 1982, 1986, 1988, 1993 67 * The Regents of the University of California. All rights reserved. 68 * 69 * Redistribution and use in source and binary forms, with or without 70 * modification, are permitted provided that the following conditions 71 * are met: 72 * 1. Redistributions of source code must retain the above copyright 73 * notice, this list of conditions and the following disclaimer. 74 * 2. Redistributions in binary form must reproduce the above copyright 75 * notice, this list of conditions and the following disclaimer in the 76 * documentation and/or other materials provided with the distribution. 77 * 3. Neither the name of the University nor the names of its contributors 78 * may be used to endorse or promote products derived from this software 79 * without specific prior written permission. 80 * 81 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 82 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 83 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 84 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 85 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 86 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 87 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 88 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 89 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 90 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 91 * SUCH DAMAGE. 92 * 93 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94 94 */ 95 96 #include <sys/cdefs.h> 97 __KERNEL_RCSID(0, "$NetBSD: ip_icmp.c,v 1.168 2018/02/08 09:32:02 maxv Exp $"); 98 99 #ifdef _KERNEL_OPT 100 #include "opt_ipsec.h" 101 #endif 102 103 #include <sys/param.h> 104 #include <sys/systm.h> 105 #include <sys/mbuf.h> 106 #include <sys/protosw.h> 107 #include <sys/socket.h> 108 #include <sys/socketvar.h> /* For softnet_lock */ 109 #include <sys/kmem.h> 110 #include <sys/time.h> 111 #include <sys/kernel.h> 112 #include <sys/syslog.h> 113 #include <sys/sysctl.h> 114 115 #include <net/if.h> 116 #include <net/route.h> 117 118 #include <netinet/in.h> 119 #include <netinet/in_systm.h> 120 #include <netinet/in_var.h> 121 #include <netinet/ip.h> 122 #include <netinet/ip_icmp.h> 123 #include <netinet/ip_var.h> 124 #include <netinet/in_pcb.h> 125 #include <netinet/in_proto.h> 126 #include <netinet/icmp_var.h> 127 #include <netinet/icmp_private.h> 128 #include <netinet/wqinput.h> 129 130 #ifdef IPSEC 131 #include <netipsec/ipsec.h> 132 #include <netipsec/key.h> 133 #endif 134 135 /* 136 * ICMP routines: error generation, receive packet processing, and 137 * routines to turnaround packets back to the originator, and 138 * host table maintenance routines. 139 */ 140 141 int icmpmaskrepl = 0; 142 int icmpbmcastecho = 0; 143 #ifdef ICMPPRINTFS 144 int icmpprintfs = 0; 145 #endif 146 int icmpreturndatabytes = 8; 147 148 percpu_t *icmpstat_percpu; 149 150 /* 151 * List of callbacks to notify when Path MTU changes are made. 152 */ 153 struct icmp_mtudisc_callback { 154 LIST_ENTRY(icmp_mtudisc_callback) mc_list; 155 void (*mc_func)(struct in_addr); 156 }; 157 158 LIST_HEAD(, icmp_mtudisc_callback) icmp_mtudisc_callbacks = 159 LIST_HEAD_INITIALIZER(&icmp_mtudisc_callbacks); 160 161 /* unused... */ 162 u_int ip_next_mtu(u_int, int); 163 164 static int icmperrppslim = 100; /* 100pps */ 165 static int icmperrpps_count = 0; 166 static struct timeval icmperrppslim_last; 167 static int icmp_rediraccept = 1; 168 static int icmp_redirtimeout = 600; 169 static struct rttimer_queue *icmp_redirect_timeout_q = NULL; 170 171 /* Protect mtudisc and redirect stuff */ 172 static kmutex_t icmp_mtx __cacheline_aligned; 173 174 static void icmp_send(struct mbuf *, struct mbuf *); 175 static void icmp_mtudisc_timeout(struct rtentry *, struct rttimer *); 176 static void icmp_redirect_timeout(struct rtentry *, struct rttimer *); 177 178 static void sysctl_netinet_icmp_setup(struct sysctllog **); 179 180 /* workqueue-based pr_input */ 181 static struct wqinput *icmp_wqinput; 182 static void _icmp_input(struct mbuf *, int, int); 183 184 void 185 icmp_init(void) 186 { 187 188 sysctl_netinet_icmp_setup(NULL); 189 190 mutex_init(&icmp_mtx, MUTEX_DEFAULT, IPL_NONE); 191 /* 192 * This is only useful if the user initializes redirtimeout to 193 * something other than zero. 194 */ 195 mutex_enter(&icmp_mtx); 196 icmp_redirect_timeout_q = rt_timer_queue_create(icmp_redirtimeout); 197 mutex_exit(&icmp_mtx); 198 199 icmpstat_percpu = percpu_alloc(sizeof(uint64_t) * ICMP_NSTATS); 200 icmp_wqinput = wqinput_create("icmp", _icmp_input); 201 } 202 203 void 204 icmp_mtudisc_lock(void) 205 { 206 207 mutex_enter(&icmp_mtx); 208 } 209 210 void 211 icmp_mtudisc_unlock(void) 212 { 213 214 mutex_exit(&icmp_mtx); 215 } 216 217 /* 218 * Register a Path MTU Discovery callback. 219 */ 220 void 221 icmp_mtudisc_callback_register(void (*func)(struct in_addr)) 222 { 223 struct icmp_mtudisc_callback *mc, *new; 224 225 new = kmem_alloc(sizeof(*mc), KM_SLEEP); 226 227 mutex_enter(&icmp_mtx); 228 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 229 mc = LIST_NEXT(mc, mc_list)) { 230 if (mc->mc_func == func) { 231 mutex_exit(&icmp_mtx); 232 kmem_free(new, sizeof(*mc)); 233 return; 234 } 235 } 236 237 new->mc_func = func; 238 LIST_INSERT_HEAD(&icmp_mtudisc_callbacks, new, mc_list); 239 mutex_exit(&icmp_mtx); 240 } 241 242 /* 243 * Generate an error packet of type error in response to a bad IP packet. 'n' 244 * contains this packet. We create 'm' and send it. 245 * 246 * As we are not required to return everything we have, we return whatever 247 * we can return at ease. 248 * 249 * Note that ICMP datagrams longer than 576 octets are out of spec according 250 * to RFC1812; the limit on icmpreturndatabytes will keep things below that 251 * limit. 252 */ 253 void 254 icmp_error(struct mbuf *n, int type, int code, n_long dest, int destmtu) 255 { 256 struct ip *oip = mtod(n, struct ip *), *nip; 257 const unsigned oiphlen = oip->ip_hl << 2; 258 struct icmp *icp; 259 struct mbuf *m; 260 struct m_tag *mtag; 261 unsigned datalen, mblen; 262 int totlen; 263 264 #ifdef ICMPPRINTFS 265 if (icmpprintfs) 266 printf("icmp_error(%p, type:%d, code:%d)\n", oip, type, code); 267 #endif 268 269 if (type != ICMP_REDIRECT) 270 ICMP_STATINC(ICMP_STAT_ERROR); 271 272 /* 273 * Don't send error if: 274 * - The original packet was encrypted. 275 * - The packet is multicast or broadcast. 276 * - The packet is not the first fragment of the message. 277 * - The packet is an ICMP message with an unknown type. 278 */ 279 if (n->m_flags & M_DECRYPTED) 280 goto freeit; 281 if (n->m_flags & (M_BCAST|M_MCAST)) 282 goto freeit; 283 if (oip->ip_off &~ htons(IP_MF|IP_DF)) 284 goto freeit; 285 if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT && 286 n->m_len >= oiphlen + ICMP_MINLEN) { 287 struct icmp *oicp = (struct icmp *)((char *)oip + oiphlen); 288 if (!ICMP_INFOTYPE(oicp->icmp_type)) { 289 ICMP_STATINC(ICMP_STAT_OLDICMP); 290 goto freeit; 291 } 292 } 293 294 /* 295 * First, do a rate limitation check. 296 */ 297 if (icmp_ratelimit(&oip->ip_src, type, code)) { 298 /* XXX stat */ 299 goto freeit; 300 } 301 302 /* 303 * Compute the number of bytes we will put in 'icmp_ip'. Truncate 304 * it to the size of the mbuf, if it's too big. 305 */ 306 datalen = oiphlen + min(icmpreturndatabytes, 307 ntohs(oip->ip_len) - oiphlen); 308 mblen = 0; 309 for (m = n; m && (mblen < datalen); m = m->m_next) 310 mblen += m->m_len; 311 datalen = min(mblen, datalen); 312 313 /* 314 * Compute the total length of the new packet. Truncate it if it's 315 * bigger than the size of a cluster. 316 */ 317 CTASSERT(ICMP_MINLEN + sizeof(struct ip) <= MCLBYTES); 318 totlen = sizeof(struct ip) + ICMP_MINLEN + datalen; 319 if (totlen > MCLBYTES) { 320 datalen = MCLBYTES - ICMP_MINLEN - sizeof(struct ip); 321 totlen = MCLBYTES; 322 } 323 324 /* 325 * Allocate the mbuf for the new packet. 326 */ 327 m = m_gethdr(M_DONTWAIT, MT_HEADER); 328 if (m && (totlen > MHLEN)) { 329 MCLGET(m, M_DONTWAIT); 330 if ((m->m_flags & M_EXT) == 0) { 331 m_freem(m); 332 m = NULL; 333 } 334 } 335 if (m == NULL) 336 goto freeit; 337 MCLAIM(m, n->m_owner); 338 m->m_len = totlen; 339 m->m_pkthdr.len = m->m_len; 340 m_copy_rcvif(m, n); 341 342 if ((u_int)type > ICMP_MAXTYPE) 343 panic("icmp_error"); 344 ICMP_STATINC(ICMP_STAT_OUTHIST + type); 345 346 if ((m->m_flags & M_EXT) == 0) 347 MH_ALIGN(m, m->m_len); 348 349 /* 350 * Get pointers on the IP header and the ICMP header. 351 */ 352 nip = mtod(m, struct ip *); 353 icp = (struct icmp *)(nip + 1); 354 355 /* 356 * Fill in the fields of the ICMP header: icmp_type, icmp_code 357 * and icmp_ip. icmp_cksum gets filled later. 358 */ 359 icp->icmp_type = type; 360 if (type == ICMP_REDIRECT) { 361 icp->icmp_gwaddr.s_addr = dest; 362 } else { 363 icp->icmp_void = 0; 364 /* 365 * The following assignments assume an overlay with the 366 * zeroed icmp_void field. 367 */ 368 if (type == ICMP_PARAMPROB) { 369 icp->icmp_pptr = code; 370 code = 0; 371 } else if (type == ICMP_UNREACH && 372 code == ICMP_UNREACH_NEEDFRAG && destmtu) 373 icp->icmp_nextmtu = htons(destmtu); 374 } 375 icp->icmp_code = code; 376 m_copydata(n, 0, datalen, (void *)&icp->icmp_ip); 377 378 /* 379 * Now, copy the old IP header (without options) in front of the 380 * ICMP message. The src/dst fields will be swapped in icmp_reflect. 381 */ 382 /* ip_v set in ip_output */ 383 nip->ip_hl = sizeof(struct ip) >> 2; 384 nip->ip_tos = 0; 385 nip->ip_len = htons(m->m_len); 386 /* ip_id set in ip_output */ 387 nip->ip_off = htons(0); 388 /* ip_ttl set in icmp_reflect */ 389 nip->ip_p = IPPROTO_ICMP; 390 nip->ip_src = oip->ip_src; 391 nip->ip_dst = oip->ip_dst; 392 /* move PF m_tag to new packet, if it exists */ 393 mtag = m_tag_find(n, PACKET_TAG_PF, NULL); 394 if (mtag != NULL) { 395 m_tag_unlink(n, mtag); 396 m_tag_prepend(m, mtag); 397 } 398 399 icmp_reflect(m); 400 401 freeit: 402 m_freem(n); 403 } 404 405 struct sockaddr_in icmpsrc = { 406 .sin_len = sizeof(struct sockaddr_in), 407 .sin_family = AF_INET, 408 }; 409 410 /* 411 * Process a received ICMP message. 412 */ 413 static void 414 _icmp_input(struct mbuf *m, int hlen, int proto) 415 { 416 struct icmp *icp; 417 struct ip *ip = mtod(m, struct ip *); 418 int icmplen; 419 int i; 420 struct in_ifaddr *ia; 421 void *(*ctlfunc)(int, const struct sockaddr *, void *); 422 int code; 423 struct rtentry *rt; 424 struct sockaddr_in icmpdst = { 425 .sin_len = sizeof(struct sockaddr_in), 426 .sin_family = AF_INET, 427 }; 428 struct sockaddr_in icmpgw = { 429 .sin_len = sizeof(struct sockaddr_in), 430 .sin_family = AF_INET, 431 }; 432 433 /* 434 * Locate icmp structure in mbuf, and check 435 * that not corrupted and of at least minimum length. 436 */ 437 icmplen = ntohs(ip->ip_len) - hlen; 438 #ifdef ICMPPRINTFS 439 if (icmpprintfs) { 440 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 441 printf("icmp_input from `%s' to `%s', len %d\n", 442 IN_PRINT(sbuf, &ip->ip_src), IN_PRINT(dbuf, &ip->ip_dst), 443 icmplen); 444 } 445 #endif 446 if (icmplen < ICMP_MINLEN) { 447 ICMP_STATINC(ICMP_STAT_TOOSHORT); 448 goto freeit; 449 } 450 i = hlen + min(icmplen, ICMP_ADVLENMIN); 451 if ((m->m_len < i || M_READONLY(m)) && (m = m_pullup(m, i)) == NULL) { 452 ICMP_STATINC(ICMP_STAT_TOOSHORT); 453 return; 454 } 455 ip = mtod(m, struct ip *); 456 m->m_len -= hlen; 457 m->m_data += hlen; 458 icp = mtod(m, struct icmp *); 459 /* Don't need to assert alignment, here. */ 460 if (in_cksum(m, icmplen)) { 461 ICMP_STATINC(ICMP_STAT_CHECKSUM); 462 goto freeit; 463 } 464 m->m_len += hlen; 465 m->m_data -= hlen; 466 467 #ifdef ICMPPRINTFS 468 /* 469 * Message type specific processing. 470 */ 471 if (icmpprintfs) 472 printf("icmp_input(type:%d, code:%d)\n", icp->icmp_type, 473 icp->icmp_code); 474 #endif 475 if (icp->icmp_type > ICMP_MAXTYPE) 476 goto raw; 477 ICMP_STATINC(ICMP_STAT_INHIST + icp->icmp_type); 478 code = icp->icmp_code; 479 480 switch (icp->icmp_type) { 481 case ICMP_UNREACH: 482 switch (code) { 483 case ICMP_UNREACH_PROTOCOL: 484 code = PRC_UNREACH_PROTOCOL; 485 break; 486 487 case ICMP_UNREACH_PORT: 488 code = PRC_UNREACH_PORT; 489 break; 490 491 case ICMP_UNREACH_SRCFAIL: 492 code = PRC_UNREACH_SRCFAIL; 493 break; 494 495 case ICMP_UNREACH_NEEDFRAG: 496 code = PRC_MSGSIZE; 497 break; 498 499 case ICMP_UNREACH_NET: 500 case ICMP_UNREACH_NET_UNKNOWN: 501 case ICMP_UNREACH_NET_PROHIB: 502 case ICMP_UNREACH_TOSNET: 503 code = PRC_UNREACH_NET; 504 break; 505 506 case ICMP_UNREACH_HOST: 507 case ICMP_UNREACH_HOST_UNKNOWN: 508 case ICMP_UNREACH_ISOLATED: 509 case ICMP_UNREACH_HOST_PROHIB: 510 case ICMP_UNREACH_TOSHOST: 511 case ICMP_UNREACH_ADMIN_PROHIBIT: 512 case ICMP_UNREACH_HOST_PREC: 513 case ICMP_UNREACH_PREC_CUTOFF: 514 code = PRC_UNREACH_HOST; 515 break; 516 517 default: 518 goto badcode; 519 } 520 goto deliver; 521 522 case ICMP_TIMXCEED: 523 if (code > 1) 524 goto badcode; 525 code += PRC_TIMXCEED_INTRANS; 526 goto deliver; 527 528 case ICMP_PARAMPROB: 529 if (code > 1) 530 goto badcode; 531 code = PRC_PARAMPROB; 532 goto deliver; 533 534 case ICMP_SOURCEQUENCH: 535 if (code) 536 goto badcode; 537 code = PRC_QUENCH; 538 goto deliver; 539 540 deliver: 541 /* 542 * Problem with datagram; advise higher level routines. 543 */ 544 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 545 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 546 ICMP_STATINC(ICMP_STAT_BADLEN); 547 goto freeit; 548 } 549 if (m->m_len < hlen + ICMP_ADVLEN(icp)) { 550 m = m_pullup(m, hlen + ICMP_ADVLEN(icp)); 551 if (m == NULL) 552 goto freeit; 553 } 554 ip = mtod(m, struct ip *); 555 icp = (struct icmp *)(mtod(m, uint8_t *) + hlen); 556 557 if (IN_MULTICAST(icp->icmp_ip.ip_dst.s_addr)) 558 goto badcode; 559 #ifdef ICMPPRINTFS 560 if (icmpprintfs) 561 printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); 562 #endif 563 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 564 ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput; 565 if (ctlfunc) 566 (void) (*ctlfunc)(code, sintosa(&icmpsrc), 567 &icp->icmp_ip); 568 break; 569 570 badcode: 571 ICMP_STATINC(ICMP_STAT_BADCODE); 572 break; 573 574 case ICMP_ECHO: 575 if (!icmpbmcastecho && 576 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 577 ICMP_STATINC(ICMP_STAT_BMCASTECHO); 578 break; 579 } 580 icp->icmp_type = ICMP_ECHOREPLY; 581 goto reflect; 582 583 case ICMP_TSTAMP: 584 if (icmplen < ICMP_TSLEN) { 585 ICMP_STATINC(ICMP_STAT_BADLEN); 586 break; 587 } 588 if (!icmpbmcastecho && 589 (m->m_flags & (M_MCAST | M_BCAST)) != 0) { 590 ICMP_STATINC(ICMP_STAT_BMCASTTSTAMP); 591 break; 592 } 593 icp->icmp_type = ICMP_TSTAMPREPLY; 594 icp->icmp_rtime = iptime(); 595 icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ 596 goto reflect; 597 598 case ICMP_MASKREQ: { 599 struct ifnet *rcvif; 600 int s, ss; 601 struct ifaddr *ifa = NULL; 602 603 if (icmpmaskrepl == 0) 604 break; 605 /* 606 * We are not able to respond with all ones broadcast 607 * unless we receive it over a point-to-point interface. 608 */ 609 if (icmplen < ICMP_MASKLEN) { 610 ICMP_STATINC(ICMP_STAT_BADLEN); 611 break; 612 } 613 if (ip->ip_dst.s_addr == INADDR_BROADCAST || 614 in_nullhost(ip->ip_dst)) 615 icmpdst.sin_addr = ip->ip_src; 616 else 617 icmpdst.sin_addr = ip->ip_dst; 618 ss = pserialize_read_enter(); 619 rcvif = m_get_rcvif(m, &s); 620 if (__predict_true(rcvif != NULL)) 621 ifa = ifaof_ifpforaddr(sintosa(&icmpdst), rcvif); 622 m_put_rcvif(rcvif, &s); 623 if (ifa == NULL) { 624 pserialize_read_exit(ss); 625 break; 626 } 627 ia = ifatoia(ifa); 628 icp->icmp_type = ICMP_MASKREPLY; 629 icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr; 630 if (in_nullhost(ip->ip_src)) { 631 if (ia->ia_ifp->if_flags & IFF_BROADCAST) 632 ip->ip_src = ia->ia_broadaddr.sin_addr; 633 else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) 634 ip->ip_src = ia->ia_dstaddr.sin_addr; 635 } 636 pserialize_read_exit(ss); 637 reflect: 638 { 639 uint64_t *icps = percpu_getref(icmpstat_percpu); 640 icps[ICMP_STAT_REFLECT]++; 641 icps[ICMP_STAT_OUTHIST + icp->icmp_type]++; 642 percpu_putref(icmpstat_percpu); 643 } 644 icmp_reflect(m); 645 return; 646 } 647 648 case ICMP_REDIRECT: 649 if (code > 3) 650 goto badcode; 651 if (icmp_rediraccept == 0) 652 goto freeit; 653 if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp) || 654 icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) { 655 ICMP_STATINC(ICMP_STAT_BADLEN); 656 break; 657 } 658 /* 659 * Short circuit routing redirects to force 660 * immediate change in the kernel's routing 661 * tables. The message is also handed to anyone 662 * listening on a raw socket (e.g. the routing 663 * daemon for use in updating its tables). 664 */ 665 icmpgw.sin_addr = ip->ip_src; 666 icmpdst.sin_addr = icp->icmp_gwaddr; 667 #ifdef ICMPPRINTFS 668 if (icmpprintfs) { 669 char gbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 670 printf("redirect dst `%s' to `%s'\n", 671 IN_PRINT(dbuf, &icp->icmp_ip.ip_dst), 672 IN_PRINT(gbuf, &icp->icmp_gwaddr)); 673 } 674 #endif 675 icmpsrc.sin_addr = icp->icmp_ip.ip_dst; 676 rt = NULL; 677 rtredirect(sintosa(&icmpsrc), sintosa(&icmpdst), 678 NULL, RTF_GATEWAY | RTF_HOST, sintosa(&icmpgw), &rt); 679 mutex_enter(&icmp_mtx); 680 if (rt != NULL && icmp_redirtimeout != 0) { 681 i = rt_timer_add(rt, icmp_redirect_timeout, 682 icmp_redirect_timeout_q); 683 if (i) { 684 char buf[INET_ADDRSTRLEN]; 685 log(LOG_ERR, "ICMP: redirect failed to " 686 "register timeout for route to %s, " 687 "code %d\n", 688 IN_PRINT(buf, &icp->icmp_ip.ip_dst), i); 689 } 690 } 691 mutex_exit(&icmp_mtx); 692 if (rt != NULL) 693 rt_unref(rt); 694 695 pfctlinput(PRC_REDIRECT_HOST, sintosa(&icmpsrc)); 696 #if defined(IPSEC) 697 if (ipsec_used) 698 key_sa_routechange((struct sockaddr *)&icmpsrc); 699 #endif 700 break; 701 702 /* 703 * No kernel processing for the following; 704 * just fall through to send to raw listener. 705 */ 706 case ICMP_ECHOREPLY: 707 case ICMP_ROUTERADVERT: 708 case ICMP_ROUTERSOLICIT: 709 case ICMP_TSTAMPREPLY: 710 case ICMP_IREQREPLY: 711 case ICMP_MASKREPLY: 712 default: 713 break; 714 } 715 716 raw: 717 rip_input(m, hlen, proto); 718 return; 719 720 freeit: 721 m_freem(m); 722 return; 723 } 724 725 void 726 icmp_input(struct mbuf *m, ...) 727 { 728 int hlen, proto; 729 va_list ap; 730 731 va_start(ap, m); 732 hlen = va_arg(ap, int); 733 proto = va_arg(ap, int); 734 va_end(ap); 735 736 wqinput_input(icmp_wqinput, m, hlen, proto); 737 } 738 739 /* 740 * Reflect the ip packet back to the source 741 */ 742 void 743 icmp_reflect(struct mbuf *m) 744 { 745 struct ip *ip = mtod(m, struct ip *); 746 struct in_ifaddr *ia; 747 struct ifaddr *ifa; 748 struct sockaddr_in *sin; 749 struct in_addr t; 750 struct mbuf *opts = NULL; 751 int optlen = (ip->ip_hl << 2) - sizeof(struct ip); 752 struct ifnet *rcvif; 753 struct psref psref, psref_ia; 754 int s; 755 int bound; 756 757 bound = curlwp_bind(); 758 759 if (!in_canforward(ip->ip_src) && 760 ((ip->ip_src.s_addr & IN_CLASSA_NET) != 761 htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) { 762 m_freem(m); /* Bad return address */ 763 goto done; /* ip_output() will check for broadcast */ 764 } 765 t = ip->ip_dst; 766 ip->ip_dst = ip->ip_src; 767 768 /* 769 * If the incoming packet was addressed directly to us, use 770 * dst as the src for the reply. Otherwise (broadcast or 771 * anonymous), use an address which corresponds to the 772 * incoming interface, with a preference for the address which 773 * corresponds to the route to the destination of the ICMP. 774 */ 775 776 /* Look for packet addressed to us */ 777 ia = in_get_ia_psref(t, &psref_ia); 778 if (ia && (ia->ia4_flags & IN_IFF_NOTREADY)) { 779 ia4_release(ia, &psref_ia); 780 ia = NULL; 781 } 782 783 rcvif = m_get_rcvif_psref(m, &psref); 784 785 /* look for packet sent to broadcast address */ 786 if (ia == NULL && rcvif && 787 (rcvif->if_flags & IFF_BROADCAST)) { 788 s = pserialize_read_enter(); 789 IFADDR_READER_FOREACH(ifa, rcvif) { 790 if (ifa->ifa_addr->sa_family != AF_INET) 791 continue; 792 if (in_hosteq(t,ifatoia(ifa)->ia_broadaddr.sin_addr)) { 793 ia = ifatoia(ifa); 794 if ((ia->ia4_flags & IN_IFF_NOTREADY) == 0) 795 break; 796 ia = NULL; 797 } 798 } 799 if (ia != NULL) 800 ia4_acquire(ia, &psref_ia); 801 pserialize_read_exit(s); 802 } 803 804 sin = ia ? &ia->ia_addr : NULL; 805 806 /* 807 * if the packet is addressed somewhere else, compute the 808 * source address for packets routed back to the source, and 809 * use that, if it's an address on the interface which 810 * received the packet 811 */ 812 if (sin == NULL && rcvif) { 813 struct sockaddr_in sin_dst; 814 struct route icmproute; 815 int errornum; 816 817 sockaddr_in_init(&sin_dst, &ip->ip_dst, 0); 818 memset(&icmproute, 0, sizeof(icmproute)); 819 errornum = 0; 820 ia = in_selectsrc(&sin_dst, &icmproute, 0, NULL, &errornum, 821 &psref_ia); 822 /* errornum is never used */ 823 rtcache_free(&icmproute); 824 /* check to make sure sin is a source address on rcvif */ 825 if (ia != NULL) { 826 sin = &ia->ia_addr; 827 t = sin->sin_addr; 828 sin = NULL; 829 ia4_release(ia, &psref_ia); 830 ia = in_get_ia_on_iface_psref(t, rcvif, &psref_ia); 831 if (ia != NULL) 832 sin = &ia->ia_addr; 833 } 834 } 835 836 /* 837 * if it was not addressed to us, but the route doesn't go out 838 * the source interface, pick an address on the source 839 * interface. This can happen when routing is asymmetric, or 840 * when the incoming packet was encapsulated 841 */ 842 if (sin == NULL && rcvif) { 843 KASSERT(ia == NULL); 844 s = pserialize_read_enter(); 845 IFADDR_READER_FOREACH(ifa, rcvif) { 846 if (ifa->ifa_addr->sa_family != AF_INET) 847 continue; 848 sin = &(ifatoia(ifa)->ia_addr); 849 ia = ifatoia(ifa); 850 ia4_acquire(ia, &psref_ia); 851 break; 852 } 853 pserialize_read_exit(s); 854 } 855 856 m_put_rcvif_psref(rcvif, &psref); 857 858 /* 859 * The following happens if the packet was not addressed to us, 860 * and was received on an interface with no IP address: 861 * We find the first AF_INET address on the first non-loopback 862 * interface. 863 */ 864 if (sin == NULL) { 865 KASSERT(ia == NULL); 866 s = pserialize_read_enter(); 867 IN_ADDRLIST_READER_FOREACH(ia) { 868 if (ia->ia_ifp->if_flags & IFF_LOOPBACK) 869 continue; 870 sin = &ia->ia_addr; 871 ia4_acquire(ia, &psref_ia); 872 break; 873 } 874 pserialize_read_exit(s); 875 } 876 877 /* 878 * If we still didn't find an address, punt. We could have an 879 * interface up (and receiving packets) with no address. 880 */ 881 if (sin == NULL) { 882 KASSERT(ia == NULL); 883 m_freem(m); 884 goto done; 885 } 886 887 ip->ip_src = sin->sin_addr; 888 ip->ip_ttl = MAXTTL; 889 890 if (ia != NULL) 891 ia4_release(ia, &psref_ia); 892 893 if (optlen > 0) { 894 u_char *cp; 895 int opt, cnt; 896 u_int len; 897 898 /* 899 * Retrieve any source routing from the incoming packet; 900 * add on any record-route or timestamp options. 901 */ 902 cp = (u_char *)(ip + 1); 903 if ((opts = ip_srcroute(m)) == NULL && 904 (opts = m_gethdr(M_DONTWAIT, MT_HEADER))) { 905 MCLAIM(opts, m->m_owner); 906 opts->m_len = sizeof(struct in_addr); 907 *mtod(opts, struct in_addr *) = zeroin_addr; 908 } 909 910 if (opts) { 911 #ifdef ICMPPRINTFS 912 if (icmpprintfs) 913 printf("icmp_reflect optlen %d rt %d => ", 914 optlen, opts->m_len); 915 #endif 916 for (cnt = optlen; cnt > 0; cnt -= len, cp += len) { 917 opt = cp[IPOPT_OPTVAL]; 918 if (opt == IPOPT_EOL) 919 break; 920 if (opt == IPOPT_NOP) 921 len = 1; 922 else { 923 if (cnt < IPOPT_OLEN + sizeof(*cp)) 924 break; 925 len = cp[IPOPT_OLEN]; 926 if (len < IPOPT_OLEN + sizeof(*cp) || 927 len > cnt) 928 break; 929 } 930 931 /* Overflows can't happen */ 932 KASSERT(opts->m_len + len <= MHLEN); 933 934 if (opt == IPOPT_RR || opt == IPOPT_TS || 935 opt == IPOPT_SECURITY) { 936 memmove(mtod(opts, char *) + 937 opts->m_len, cp, len); 938 opts->m_len += len; 939 } 940 } 941 942 /* Terminate & pad, if necessary */ 943 if ((cnt = opts->m_len % 4) != 0) { 944 for (; cnt < 4; cnt++) { 945 *(mtod(opts, char *) + opts->m_len) = 946 IPOPT_EOL; 947 opts->m_len++; 948 } 949 } 950 #ifdef ICMPPRINTFS 951 if (icmpprintfs) 952 printf("%d\n", opts->m_len); 953 #endif 954 } 955 956 /* 957 * Now strip out original options by copying rest of first 958 * mbuf's data back, and adjust the IP length. 959 */ 960 ip->ip_len = htons(ntohs(ip->ip_len) - optlen); 961 ip->ip_hl = sizeof(struct ip) >> 2; 962 m->m_len -= optlen; 963 if (m->m_flags & M_PKTHDR) 964 m->m_pkthdr.len -= optlen; 965 optlen += sizeof(struct ip); 966 memmove(ip + 1, (char *)ip + optlen, 967 (unsigned)(m->m_len - sizeof(struct ip))); 968 } 969 m_tag_delete_nonpersistent(m); 970 m->m_flags &= ~(M_BCAST|M_MCAST); 971 972 /* 973 * Clear any in-bound checksum flags for this packet. 974 */ 975 if (m->m_flags & M_PKTHDR) 976 m->m_pkthdr.csum_flags = 0; 977 978 icmp_send(m, opts); 979 done: 980 curlwp_bindx(bound); 981 if (opts) 982 (void)m_free(opts); 983 } 984 985 /* 986 * Send an icmp packet back to the ip level, 987 * after supplying a checksum. 988 */ 989 static void 990 icmp_send(struct mbuf *m, struct mbuf *opts) 991 { 992 struct ip *ip = mtod(m, struct ip *); 993 int hlen; 994 struct icmp *icp; 995 996 hlen = ip->ip_hl << 2; 997 m->m_data += hlen; 998 m->m_len -= hlen; 999 icp = mtod(m, struct icmp *); 1000 icp->icmp_cksum = 0; 1001 icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen); 1002 m->m_data -= hlen; 1003 m->m_len += hlen; 1004 #ifdef ICMPPRINTFS 1005 if (icmpprintfs) { 1006 char sbuf[INET_ADDRSTRLEN], dbuf[INET_ADDRSTRLEN]; 1007 printf("icmp_send to destination `%s' from `%s'\n", 1008 IN_PRINT(dbuf, &ip->ip_dst), IN_PRINT(sbuf, &ip->ip_src)); 1009 } 1010 #endif 1011 (void)ip_output(m, opts, NULL, 0, NULL, NULL); 1012 } 1013 1014 n_time 1015 iptime(void) 1016 { 1017 struct timeval atv; 1018 u_long t; 1019 1020 microtime(&atv); 1021 t = (atv.tv_sec % (24*60*60)) * 1000 + atv.tv_usec / 1000; 1022 return (htonl(t)); 1023 } 1024 1025 /* 1026 * sysctl helper routine for net.inet.icmp.returndatabytes. ensures 1027 * that the new value is in the correct range. 1028 */ 1029 static int 1030 sysctl_net_inet_icmp_returndatabytes(SYSCTLFN_ARGS) 1031 { 1032 int error, t; 1033 struct sysctlnode node; 1034 1035 node = *rnode; 1036 node.sysctl_data = &t; 1037 t = icmpreturndatabytes; 1038 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1039 if (error || newp == NULL) 1040 return error; 1041 1042 if (t < 8 || t > 512) 1043 return EINVAL; 1044 icmpreturndatabytes = t; 1045 1046 return 0; 1047 } 1048 1049 /* 1050 * sysctl helper routine for net.inet.icmp.redirtimeout. ensures that 1051 * the given value is not less than zero and then resets the timeout 1052 * queue. 1053 */ 1054 static int 1055 sysctl_net_inet_icmp_redirtimeout(SYSCTLFN_ARGS) 1056 { 1057 int error, tmp; 1058 struct sysctlnode node; 1059 1060 mutex_enter(&icmp_mtx); 1061 1062 node = *rnode; 1063 node.sysctl_data = &tmp; 1064 tmp = icmp_redirtimeout; 1065 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1066 if (error || newp == NULL) 1067 goto out; 1068 if (tmp < 0) { 1069 error = EINVAL; 1070 goto out; 1071 } 1072 icmp_redirtimeout = tmp; 1073 1074 /* 1075 * was it a *defined* side-effect that anyone even *reading* 1076 * this value causes these things to happen? 1077 */ 1078 if (icmp_redirect_timeout_q != NULL) { 1079 if (icmp_redirtimeout == 0) { 1080 rt_timer_queue_destroy(icmp_redirect_timeout_q); 1081 icmp_redirect_timeout_q = NULL; 1082 } else { 1083 rt_timer_queue_change(icmp_redirect_timeout_q, 1084 icmp_redirtimeout); 1085 } 1086 } else if (icmp_redirtimeout > 0) { 1087 icmp_redirect_timeout_q = 1088 rt_timer_queue_create(icmp_redirtimeout); 1089 } 1090 error = 0; 1091 out: 1092 mutex_exit(&icmp_mtx); 1093 return error; 1094 } 1095 1096 static int 1097 sysctl_net_inet_icmp_stats(SYSCTLFN_ARGS) 1098 { 1099 1100 return (NETSTAT_SYSCTL(icmpstat_percpu, ICMP_NSTATS)); 1101 } 1102 1103 static void 1104 sysctl_netinet_icmp_setup(struct sysctllog **clog) 1105 { 1106 1107 sysctl_createv(clog, 0, NULL, NULL, 1108 CTLFLAG_PERMANENT, 1109 CTLTYPE_NODE, "inet", NULL, 1110 NULL, 0, NULL, 0, 1111 CTL_NET, PF_INET, CTL_EOL); 1112 sysctl_createv(clog, 0, NULL, NULL, 1113 CTLFLAG_PERMANENT, 1114 CTLTYPE_NODE, "icmp", 1115 SYSCTL_DESCR("ICMPv4 related settings"), 1116 NULL, 0, NULL, 0, 1117 CTL_NET, PF_INET, IPPROTO_ICMP, CTL_EOL); 1118 1119 sysctl_createv(clog, 0, NULL, NULL, 1120 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1121 CTLTYPE_INT, "maskrepl", 1122 SYSCTL_DESCR("Respond to ICMP_MASKREQ messages"), 1123 NULL, 0, &icmpmaskrepl, 0, 1124 CTL_NET, PF_INET, IPPROTO_ICMP, 1125 ICMPCTL_MASKREPL, CTL_EOL); 1126 sysctl_createv(clog, 0, NULL, NULL, 1127 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1128 CTLTYPE_INT, "returndatabytes", 1129 SYSCTL_DESCR("Number of bytes to return in an ICMP " 1130 "error message"), 1131 sysctl_net_inet_icmp_returndatabytes, 0, 1132 &icmpreturndatabytes, 0, 1133 CTL_NET, PF_INET, IPPROTO_ICMP, 1134 ICMPCTL_RETURNDATABYTES, CTL_EOL); 1135 sysctl_createv(clog, 0, NULL, NULL, 1136 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1137 CTLTYPE_INT, "errppslimit", 1138 SYSCTL_DESCR("Maximum number of outgoing ICMP error " 1139 "messages per second"), 1140 NULL, 0, &icmperrppslim, 0, 1141 CTL_NET, PF_INET, IPPROTO_ICMP, 1142 ICMPCTL_ERRPPSLIMIT, CTL_EOL); 1143 sysctl_createv(clog, 0, NULL, NULL, 1144 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1145 CTLTYPE_INT, "rediraccept", 1146 SYSCTL_DESCR("Accept ICMP_REDIRECT messages"), 1147 NULL, 0, &icmp_rediraccept, 0, 1148 CTL_NET, PF_INET, IPPROTO_ICMP, 1149 ICMPCTL_REDIRACCEPT, CTL_EOL); 1150 sysctl_createv(clog, 0, NULL, NULL, 1151 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1152 CTLTYPE_INT, "redirtimeout", 1153 SYSCTL_DESCR("Lifetime of ICMP_REDIRECT generated " 1154 "routes"), 1155 sysctl_net_inet_icmp_redirtimeout, 0, 1156 &icmp_redirtimeout, 0, 1157 CTL_NET, PF_INET, IPPROTO_ICMP, 1158 ICMPCTL_REDIRTIMEOUT, CTL_EOL); 1159 sysctl_createv(clog, 0, NULL, NULL, 1160 CTLFLAG_PERMANENT, 1161 CTLTYPE_STRUCT, "stats", 1162 SYSCTL_DESCR("ICMP statistics"), 1163 sysctl_net_inet_icmp_stats, 0, NULL, 0, 1164 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_STATS, 1165 CTL_EOL); 1166 sysctl_createv(clog, 0, NULL, NULL, 1167 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 1168 CTLTYPE_INT, "bmcastecho", 1169 SYSCTL_DESCR("Respond to ICMP_ECHO or ICMP_TIMESTAMP " 1170 "message to the broadcast or multicast"), 1171 NULL, 0, &icmpbmcastecho, 0, 1172 CTL_NET, PF_INET, IPPROTO_ICMP, ICMPCTL_BMCASTECHO, 1173 CTL_EOL); 1174 } 1175 1176 void 1177 icmp_statinc(u_int stat) 1178 { 1179 1180 KASSERT(stat < ICMP_NSTATS); 1181 ICMP_STATINC(stat); 1182 } 1183 1184 /* Table of common MTUs */ 1185 static const u_int mtu_table[] = { 1186 65535, 65280, 32000, 17914, 9180, 8166, 1187 4352, 2002, 1492, 1006, 508, 296, 68, 0 1188 }; 1189 1190 void 1191 icmp_mtudisc(struct icmp *icp, struct in_addr faddr) 1192 { 1193 struct icmp_mtudisc_callback *mc; 1194 struct sockaddr *dst = sintosa(&icmpsrc); 1195 struct rtentry *rt; 1196 u_long mtu = ntohs(icp->icmp_nextmtu); /* Why a long? IPv6 */ 1197 int error; 1198 1199 rt = rtalloc1(dst, 1); 1200 if (rt == NULL) 1201 return; 1202 1203 /* If we didn't get a host route, allocate one */ 1204 if ((rt->rt_flags & RTF_HOST) == 0) { 1205 struct rtentry *nrt; 1206 1207 error = rtrequest(RTM_ADD, dst, rt->rt_gateway, NULL, 1208 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt); 1209 if (error) { 1210 rt_unref(rt); 1211 return; 1212 } 1213 nrt->rt_rmx = rt->rt_rmx; 1214 rt_unref(rt); 1215 rt = nrt; 1216 } 1217 1218 mutex_enter(&icmp_mtx); 1219 error = rt_timer_add(rt, icmp_mtudisc_timeout, ip_mtudisc_timeout_q); 1220 mutex_exit(&icmp_mtx); 1221 if (error) { 1222 rt_unref(rt); 1223 return; 1224 } 1225 1226 if (mtu == 0) { 1227 int i = 0; 1228 1229 mtu = ntohs(icp->icmp_ip.ip_len); 1230 /* Some 4.2BSD-based routers incorrectly adjust the ip_len */ 1231 if (mtu > rt->rt_rmx.rmx_mtu && rt->rt_rmx.rmx_mtu != 0) 1232 mtu -= (icp->icmp_ip.ip_hl << 2); 1233 1234 /* If we still can't guess a value, try the route */ 1235 if (mtu == 0) { 1236 mtu = rt->rt_rmx.rmx_mtu; 1237 1238 /* If no route mtu, default to the interface mtu */ 1239 if (mtu == 0) 1240 mtu = rt->rt_ifp->if_mtu; 1241 } 1242 1243 for (i = 0; i < sizeof(mtu_table) / sizeof(mtu_table[0]); i++) { 1244 if (mtu > mtu_table[i]) { 1245 mtu = mtu_table[i]; 1246 break; 1247 } 1248 } 1249 } 1250 1251 /* 1252 * XXX: RTV_MTU is overloaded, since the admin can set it 1253 * to turn off PMTU for a route, and the kernel can 1254 * set it to indicate a serious problem with PMTU 1255 * on a route. We should be using a separate flag 1256 * for the kernel to indicate this. 1257 */ 1258 1259 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1260 if (mtu < 296 || mtu > rt->rt_ifp->if_mtu) 1261 rt->rt_rmx.rmx_locks |= RTV_MTU; 1262 else if (rt->rt_rmx.rmx_mtu > mtu || 1263 rt->rt_rmx.rmx_mtu == 0) { 1264 ICMP_STATINC(ICMP_STAT_PMTUCHG); 1265 rt->rt_rmx.rmx_mtu = mtu; 1266 } 1267 } 1268 1269 if (rt != NULL) 1270 rt_unref(rt); 1271 1272 /* 1273 * Notify protocols that the MTU for this destination 1274 * has changed. 1275 */ 1276 mutex_enter(&icmp_mtx); 1277 for (mc = LIST_FIRST(&icmp_mtudisc_callbacks); mc != NULL; 1278 mc = LIST_NEXT(mc, mc_list)) 1279 (*mc->mc_func)(faddr); 1280 mutex_exit(&icmp_mtx); 1281 } 1282 1283 /* 1284 * Return the next larger or smaller MTU plateau (table from RFC 1191) 1285 * given current value MTU. If DIR is less than zero, a larger plateau 1286 * is returned; otherwise, a smaller value is returned. 1287 */ 1288 u_int 1289 ip_next_mtu(u_int mtu, int dir) /* XXX unused */ 1290 { 1291 int i; 1292 1293 for (i = 0; i < (sizeof mtu_table) / (sizeof mtu_table[0]); i++) { 1294 if (mtu >= mtu_table[i]) 1295 break; 1296 } 1297 1298 if (dir < 0) { 1299 if (i == 0) { 1300 return 0; 1301 } else { 1302 return mtu_table[i - 1]; 1303 } 1304 } else { 1305 if (mtu_table[i] == 0) { 1306 return 0; 1307 } else if (mtu > mtu_table[i]) { 1308 return mtu_table[i]; 1309 } else { 1310 return mtu_table[i + 1]; 1311 } 1312 } 1313 } 1314 1315 static void 1316 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r) 1317 { 1318 1319 KASSERT(rt != NULL); 1320 rt_assert_referenced(rt); 1321 1322 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1323 (RTF_DYNAMIC | RTF_HOST)) { 1324 rtrequest(RTM_DELETE, rt_getkey(rt), 1325 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1326 } else { 1327 if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) { 1328 rt->rt_rmx.rmx_mtu = 0; 1329 } 1330 } 1331 } 1332 1333 static void 1334 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r) 1335 { 1336 1337 KASSERT(rt != NULL); 1338 rt_assert_referenced(rt); 1339 1340 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) == 1341 (RTF_DYNAMIC | RTF_HOST)) { 1342 rtrequest(RTM_DELETE, rt_getkey(rt), 1343 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); 1344 } 1345 } 1346 1347 /* 1348 * Perform rate limit check. 1349 * Returns 0 if it is okay to send the icmp packet. 1350 * Returns 1 if the router SHOULD NOT send this icmp packet due to rate 1351 * limitation. 1352 * 1353 * XXX per-destination/type check necessary? 1354 */ 1355 int 1356 icmp_ratelimit(const struct in_addr *dst, const int type, 1357 const int code) 1358 { 1359 1360 /* PPS limit */ 1361 if (!ppsratecheck(&icmperrppslim_last, &icmperrpps_count, 1362 icmperrppslim)) { 1363 /* The packet is subject to rate limit */ 1364 return 1; 1365 } 1366 1367 /* okay to send */ 1368 return 0; 1369 } 1370
Indexes created Fri Sep 26 08:10:20 GMT 2025